This invention relates generally to apparatus for controlling the discharge of water or other liquids from a container. More particularly, the present invention is directed to a drain assembly for bathtubs, sinks and the like.
Drain assemblies are well known and generally comprise two types. The first type utilizes separate components such as a drain seat and a rubber plug. The plug is manually inserted into the drain seat, sealing the drain at the seating surface. Such drain assemblies are subject to several problems. The rubber plug is not attached to the assembly and may be lost. The rubber plug is subject to wear and damage. A worn or damaged plug may not provide a tight seal with the seating surface, allowing water to drain from the bathtub. The plug may be seated too forcefully, making it difficult or impossible to remove the plug without damage to the plug and or seating surface.
The second type utilizes an integral assembly which comprises a drain seat and a metal plug. A lever mechanism or equivalent actuator is employed to seat and unseat the metal plug. Such lever operated actuators are difficult or impossible to repair or replace should they become damaged or inoperable due to wear or loss of parts. Additionally such drain assemblies may not be suitable for bathtubs or sinks that were not designed for their use. Alternatively, in drains of the second type, the metal plug may have a "handle" that is used to manually position the plug. The drain assembly shown in U.S. Pat. No. 4,926,507, for example, employs the arms of a U-shaped metallic spring to frictionally grip opposed flats on a center post that projects from the plug bottom. The frictional force holds the plug in the selected plug position. Wear between the spring and post flats can reduce the frictional force, preventing the spring from holding the plug in an open position. As a further disadvantage of this type of drain assembly, the plug is often provided with a resilient seal member which is subject to relatively rapid wear and is difficult or impossible to replace.